J/ApJS/279/54 The CatSouth and CatGlobe QSO candidate catalogs (Fu+, 2025)
The CatSouth quasar candidate catalog for the southern sky and a unified all-sky
catalog based on Gaia DR3.
Fu Y., Wu X.-B., Bouwens R.J., Caputi K.I., Pang Y., Zhu R., Yang D.-M.,
Qin J., Wang H., Wolf C., Li Y., Joshi R., Zhang Y., Huo Z.-Y., Ai Y.L.
<Astrophys. J. Suppl. Ser., 279, 54 (2025)>
=2025ApJS..279...54F 2025ApJS..279...54F
ADC_Keywords: QSOs; Proper motions; Optical; Photometry, infrared; Redshifts
Keywords: Active galactic nuclei ; Astrostatistics techniques ; Catalogs ;
Classification ; Quasars ; Redshift surveys
Abstract:
The Gaia DR3 has provided a large sample of more than 6.6 million
quasar candidates with high completeness but low purity. Previous work
on the CatNorth quasar candidate catalog has shown that including
external multiband data and applying machine learning methods can
efficiently purify the original Gaia DR3 quasar candidate catalog and
improve the redshift estimates. In this paper, we extend the Gaia DR3
quasar candidate selection to the Southern Hemisphere using data from
SkyMapper, CatWISE, and Visible and Infrared Survey Telescope for
Astronomy surveys. We train an XGBoost classifier on a unified set of
high-confidence stars and spectroscopically confirmed quasars and
galaxies. For sources with available Gaia BP/RP spectra, spectroscopic
redshifts are derived using a pretrained convolutional neural network
(RegNet). We also train an ensemble photometric redshift estimation
model based on XGBoost, TabNet, and FT-Transformer, achieving a root
mean square error of 0.2256 and a normalized median absolute deviation
of 0.0187 on the validation set. By merging CatSouth with the
previously published CatNorth catalog, we construct the unified
all-sky CatGlobe catalog with nearly 1.9 million sources at G<21,
providing a comprehensive and high-purity quasar candidate sample for
future spectroscopic and cosmological investigations.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 538 921528 CatSouth quasar candidate catalog
table4.dat 314 1889813 CatGlobe quasar candidate catalog
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See also:
VII/250 : The 2dF Galaxy Redshift Survey (2dFGRS) (2dFGRS Team, 1998-2003)
III/227 : General Catalog of galactic Carbon stars, 3d Ed. (Alksnis+ 2001)
VII/241 : The 2dF QSO Redshift Survey (Croom+ 2004)
VII/233 : 2MASS All-Sky Extended Source Catalog (XSC) (IPAC/UMass, 2003-2006)
VII/259 : 6dF galaxy survey final redshift release (Jones+, 2009)
I/323 : International Celestial Reference Frame 2, ICRF2 (Ma+, 2009)
II/351 : VISTA Magellanic Survey (VMC) catalog (Cioni+, 2011)
II/375 : VISTA Magellanic Survey (VMC) catalog (YJKs) DR6 (Cioni+, 2011)
II/329 : VIKING catalogue data release 1 (Edge+, 2013)
III/334 : VISTA Deep Extragalactic Observations (VIDEO) (Jarvis+, 2013)
II/359 : The VISTA Hemisphere Survey (VHS) catalog DR4.1 (McMahon+, 2013)
II/343 : VIKING catalogue data release 2 (Edge+, 2016)
II/358 : SkyMapper Southern Sky Survey. DR1.1 (Wolf+, 2018)
II/373 : The fourth UltraVISTA data release (DR4) (Moneti+, 2019)
I/350 : Gaia EDR3 (Gaia Collaboration, 2020)
II/367 : The VISTA Hemisphere Survey (VHS) catalog DR5 (McMahon+, 2020)
V/154 : Sloan Digital Sky Surveys (SDSS), Release 16 (DR16) (Ahumada+, 2020)
VII/289 : SDSS quasar catalog, sixteenth data release (DR16Q) (Lyke+, 2020)
VII/294 : The Million Quasars (Milliquas) catalogue, version 8 (Flesch, 2023)
II/379 : SkyMapper Southern Sky Survey. DR4 (Onken+, 2024)
J/A+A/358/77 : Hamburg/ESO survey for bright QSOs. III. (Wisotzki+, 2000)
J/ApJS/165/1 : BAL QSOs from SDSS DR3 (Trump+, 2006)
J/MNRAS/386/1605 : Luminous K-band selected QSOs from UKIDSS (Maddox+, 2008)
J/MNRAS/406/1583 : Quasar from SDSS and UKIDSS (Wu+, 2010)
J/AJ/141/97 : SDSS DR7 M dwarfs (West+, 2011)
J/ApJS/199/26 : The 2MASS Redshift Survey (2MRS) (Huchra+, 2012)
J/A+A/544/A156 : UltraVISTA Catalogue Release DR1 (McCracken+, 2012)
J/AJ/144/49 : Quasars from SDSS-DR7, WISE and UKIDSS surveys (Wu+, 2012)
J/AJ/151/24 : LAMOST QSO survey: quasar properties from DR1 (Ai+, 2016)
J/ApJS/234/23 : The WISE AGN candidates catalogs (Assef+, 2018)
II/365 : The CatWISE2020 cat. (updated version 28-Jan-2021) (Marocco+, 2021)
III/286 : APOGEE-2 DR17 final allStar catalog (Abdurro'uf+, 2022)
I/357 : Gaia DR3 Part 3. Non-single stars (Gaia Collaboration, 2022)
J/AJ/155/189 : LAMOST Quasar Survey: QSO data from DR2&3 (Dong+, 2018)
J/ApJ/887/268 : Bright QSOs in Southern Hemisphere (Calderone+, 2019)
J/ApJS/240/6 : LAMOST Quasar Survey: Data Releases 4 and 5 (Yao+, 2019)
J/ApJ/872/134 : A uniformly selected, all-sky, optical AGN cat. (Zaw+, 2019)
J/ApJS/250/26 : Spectroscopic follow-up of the QUBRICS QSOs (Boutsia+, 2020)
J/ApJS/250/17 : NGVS. XXXIV. Ultracompact dwarf galaxies in Virgo (Liu+, 2020)
J/ApJS/254/6 : Finding QSOs behind the Galactic Plane. I. (Fu+, 2021)
J/A+A/649/A3 : Gaia EDR3 photometric passbands (Riello+, 2021)
J/ApJS/261/32 : Finding GPQs. II. Sp. obs. of |b|<20° QSOs (Fu+, 2022)
J/A+A/668/A99 : Gaia DR3 quasar and galaxy classification (Hughes+, 2022)
J/MNRAS/511/572 : High-redshift Ultralum. QSOs with SMSS DR3 (Onken+, 2022)
J/A+A/674/A41 : Composite quasar spectra from Gaia DR3 (Gaia Coll., 2023)
J/A+A/674/A39 : Gaia DR3. 95 extrasolar planets (Gaia Coll.+, 2023)
J/ApJS/265/25 : LAMOST Quasar Survey DR6-DR9 (Jin+, 2023)
J/ApJS/264/9 : Southern phot. QSOs from DES DR2 & NIR surveys (Yang+, 2023)
J/ApJS/271/54 : CatNorth: improved GaiaDR3 QSO cat. with PS1&WISE (Fu+, 2024)
J/ApJS/275/46 : Unobscured QSO cand. in the southern sky with KS4 (Kim+, 2024)
J/ApJ/964/69 : Quaia, the Gaia-unWISE Quasar catalog (Storey-Fisher+, 2024)
J/ApJS/271/19 : FGK dwarfs from LAMOST DR7 and Gaia DR3 and Kepler (Ye+, 2024)
J/MNRAS/536/3611 : Broad-line AGN in 6dF Galaxy Survey (Hon+, 2025)
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaDR3 Gaia DR3 unique source identifier
(source_id)
21- 30 E10.5 deg RAdeg Gaia DR3 Right ascension (ICRS) at
Ep=2016.0 (ra)
32- 42 E11.6 deg DEdeg [-90/29] Gaia DR3 Declination (ICRS)
at Ep=2016.0 (dec)
44- 53 E10.6 deg GLON Galactic longitude (l)
55- 66 F12.8 deg GLAT [-90/80] Galactic latitude (b)
68- 72 F5.1 mas plx [-11.7/14] Parallax (parallax)
74- 76 F3.1 mas e_plx [0/4.6] Standard error on plx
(parallax_error)
78- 81 F4.1 mas/yr pmRA [-8.6/8.8] Proper motion in right
ascension direction (pmra)
83- 85 F3.1 mas/yr e_pmRA [0/3.3] Standard error of pmra
(pmra_error)
87- 90 F4.1 mas/yr pmDE [-9.9/9.6] Proper motion in
declination direction (pmdec)
92- 94 F3.1 mas/yr e_pmDE [0/3.3] Standard error of pmdec
(pmdec_error)
96- 99 F4.1 --- pmRApmDEcor [-0.9/0.9] Correlation between pmra
and pmdec (pmra-pmdec-corr)
101- 107 F7.4 mag BPmag [12.9/23]? Integrated BP mean AB
magnitude (phot-bp-mean-mag)
109- 115 F7.4 mag Gmag [12.8/21.3]? G-band mean AB magnitude
(phot-g-mean-mag)
117- 123 F7.4 mag RPmag [12.49/21.9]? Integrated RP mean AB
magnitude (phot-rp-mean-mag)
125- 131 E7.4 mag BP-RP [-1.5/4.3]? BP-RP color (bp-rp)
133- 138 F6.4 --- E(BP/RP) [0.5/5.7]? BP/RP excess factor
(phot-bp-rp-excess-factor)
140- 149 I10 --- SMSS [66/2724323161] SMSS DR4 unique object
id (smss_id)
151- 160 E10.6 deg RASdeg SMSS DR4 Right ascension (ICRS)
(ra_smss)
162- 172 E11.6 deg DESdeg SMSS DR4 Declination (ICRS) (dec_smss)
174- 181 F8.3 --- chi2-psf [0/7583]? Maximum chi-squared from
photometry table (chi2_psf)
183- 188 F6.3 mag g-psf [11.3/24.6]? Weighted mean SMSS g-band
PSF AB magnitude (g_psf)
190- 194 F5.3 mag e_g-psf [0/1.9]? Error in g-psf (egpsf)
196- 201 F6.3 mag r-psf [13/23.8]? Weighted mean SMSS r-band
PSF AB magnitude
203- 207 F5.3 mag e_r-psf [0/1.4]? Error in r-psf
209- 214 F6.3 mag i-psf [12.7/23.3]? Weighted mean SMSS i-band
PSF AB magnitude
216- 220 F5.3 mag e_i-psf [0/1.6]? Error in i-psf
222- 227 F6.3 mag z-psf [11.9/22.6]? Weighted mean SMSS z-band
PSF AB magnitude
229- 233 F5.3 mag e_z-psf [0/1.6]? Error in z-psf
235- 240 F6.3 mag Yapmag3 [10.9/22.2]? Default point source Y
aperture corrected Vega mag
(2" diameter) (yapermag3)
242- 246 F5.3 mag e_Yapmag3 [0/1.2]? Error in Yapmag3
(yapermag3err)
248- 253 F6.3 mag Japmag3 [10.89/22.3]? Default point source J
aperture corrected Vega mag
(2" diameter) (japermag3)
255- 259 F5.3 mag e_Japmag3 [0.001/1.9]? Error in Japmag3
(japermag3err)
261- 271 E11.3 mag Hapmag3 [8.8/20.3]? Default point source H
aperture corrected Vega mag
(2 arcsec diameter) (hapermag3)
273- 283 E11.3 mag e_Hapmag3 [0.001/0.6]? Error in Hapmag3
(hapermag3err)
285- 290 F6.3 mag Ksapmag3 [7.57/20]? Default point source Ks
aperture corrected Vega mag
(2 arcsec diameter) (ksapermag3)
292- 296 F5.3 mag e_Ksapmag3 [0.001/1.1]? Error in Ksapmag3
(ksapermag3err)
298- 315 A18 --- CatWISE CatWISE2020 source id (catwise_id)
317- 326 E10.6 deg RACdeg CatWISE2020 Right Ascension (ICRS)
(ra_cat)
328- 338 E11.6 deg DECdeg CatWISE2020 Declination (ICRS)
(dec_cat)
340- 347 E8.3 arcsec/yr pmRACW [-6/2.7] CatWISE2020 proper motion in
right ascension direction (pmra_cat)
349- 356 E8.3 arcsec/yr pmDECW [-8.4/5.8] CatWISE2020 proper motion
in declination direction (pmdec_cat)
358- 363 F6.4 arcsec/yr e_pmRACW [0.001/1.4] Uncertainty in pmRACW
(epmracat)
365- 370 F6.4 arcsec/yr e_pmDECW [0.0016/1.3] Uncertainty in pmDECW
(epmdeccat)
372- 376 F5.1 --- snrw1pm [0.1/176.5]? Flux S/N ratio in band-1
(W1) (snrw1pm)
378- 382 F5.1 --- snrw2pm [0/443.3]? Flux S/N ratio in band-2
(W2) (snrw2pm)
384- 388 F5.1 --- snrw3 [-96.4/91]? Flux S/N ratio in band-3
(W3) from AllWISE (snrw3)
390- 395 F6.3 mag W1mag [7.2/21.1] WPRO magnitude in band-1
(Vega) (w1mpropm)
397- 401 F5.3 mag e_W1mag [0.006/0.6]? Uncertainty in W1mag
(e_w1mpropm)
403- 408 F6.3 mag W2mag [6/20.9] WPRO magnitude in band-2
(Vega) (w2mpropm)
410- 414 F5.3 mag e_W2mag [0.002/0.6]? Uncertainty in W2mag
416- 421 F6.3 mag W3mag [1.9/14]? WPRO magnitude in band-3
from AllWISE (Vega) (w3mpro)
423- 427 F5.3 mag e_W3mag [0.01/0.6]? Uncertainty in W3mag from
AllWISE
429- 435 E7.3 --- E(BP/RP)c [-0.62/4.4]? Corrected E(BP/RP)
(phot-bp-rp-excess-factor-c)
437- 442 F6.3 [-] logfpm0 [-4/2.8] Logarithm probability density
of zero proper motion (logfpm0)
444- 448 A5 --- in-lmc Set to True if within 10 degree from
the center of LMC; False otherwise
(in_lmc)
450- 454 A5 --- in-smc Set to True if within 5 degree from
the center of SMC; False otherwise
(in_smc)
456- 463 F8.4 --- zGaia [0.08/6.2]?=-99.99 Redshift estimate
from Gaia DR3 QSO candidate table
(z_gaia)
465- 472 F8.4 --- b_zGaia ?=-99.99 Lower confidence interval of
z-gaia taken at 0.15866 quantile
(zgaialow)
474- 481 F8.4 --- B_zGaia ?=-99.99 Upper confidence interval of
z-gaia taken at 0.84134 quantile
(zgaiaup)
483- 487 F5.3 --- pGal [0/0.5] XGBoost probability of the
object being a galaxy (p_gal)
489- 493 F5.3 --- pQSO [0.3/1] XGBoost probability of the
object being a quasar (p_qso)
495- 499 F5.3 --- pStar [0/0.5] XGBoost probability of the
object being a star (p_star)
501- 507 E7.4 --- zphXGB [-0.12/4.6] Photometric redshift
predicted with XGBoost (zphxgb)
509- 515 E7.4 --- zphTabN [-0.7/7.5] Photometric redshift
predicted with TabNet (zphtab)
517- 523 F7.4 --- zphFTT [-0.03/5.7] Photometric redshift
predicted with FT-Transformer
(zphftt)
525- 531 F7.4 --- zph [-0.21/5.2] Ensemble photometric
redshift (mean of zph-xgb, zph-tab,
and zph-ftt) (z_ph)
533- 538 F6.4 --- zxp-nn [0.01/4.5]? Spectral redshift
predicted with RegNet using Gaia
low-res spectroscopy (zxpnn)
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaDR3 Gaia DR3 unique source identifier
(source_id)
21- 30 E10.5 deg RAdeg Gaia DR3 Right ascension (ICRS) at
Ep=2016.0 (ra)
32- 42 E11.6 deg DEdeg [-90/90] Gaia DR3 Declination (ICRS)
at Ep=2016.0 (dec)
44- 53 E10.5 deg GLON Galactic longitude (l)
55- 66 F12.8 deg GLAT [-90/90] Galactic latitude (b)
68- 74 F7.3 mas plx [-11.7/14]? Parallax (parallax)
76- 80 F5.3 mas e_plx [0.013/4.8]? Standard error of parallax
(parallax_error)
82- 88 F7.3 mas/yr pmRA [-10.02/9.5]? Proper motion in right
ascension direction (pmra)
90- 94 F5.3 mas/yr e_pmRA [0.01/3.4]? Standard error of pmra
(pmra_error)
96- 101 F6.3 mas/yr pmDE [-9.9/9.6]? Proper motion in declination
direction (pmdec)
103- 107 F5.3 mas/yr e_pmDE [0.013/3.4]? Standard error of pmdec
(pmdec_error)
109- 114 F6.3 --- pmRApmDEcor [-0.93/0.93]? Correlation between pmra
and pmdec (pmra-pmdec-corr)
116- 122 F7.4 mag BPmag [9.9/24]? Integrated BP mean AB magnitude
(phot-bp-mean-mag)
124- 130 F7.4 mag Gmag [10.3/21.9]? G-band mean AB magnitude
(phot-g-mean-mag)
132- 138 F7.4 mag RPmag [9.4/23.6]? Integrated RP mean AB
magnitude (phot-rp-mean-mag)
140- 146 E7.4 mag BP-RP [-4/4.3]? BP-RP color (bp-rp)
148- 154 F7.4 --- E(BP/RP) [0.29/43.05]? BP/RP excess factor
(phot-bp-rp-excess-factor)
156- 173 A18 --- CatWISE CatWISE2020 source id (catwise_id)
175- 184 E10.5 deg RACdeg CatWISE2020 Right Ascension (ICRS)
(ra_cat)
186- 196 E11.6 deg DECdeg CatWISE2020 Declination (ICRS) (dec_cat)
198- 202 F5.1 --- snrw1pm [0.1/323.5]? Flux S/N ratio in band-1 (W1)
(snrw1pm)
204- 209 F6.1 --- snrw2pm [0/1839.3]? Flux S/N ratio in band-2 (W2)
(snrw2pm)
211- 216 F6.3 mag W1mag [7.2/21.04] WPRO magnitude in band-1
(Vega) (w1mpro_pm)
218- 222 F5.3 mag e_W1mag [0.003/0.6]? Uncertainty in W1mag
(e_w1mpropm)
224- 229 F6.3 mag W2mag [6/20.9] WPRO magnitude in band-2 (Vega)
(w2mpro_pm)
231- 235 F5.3 mag e_W2mag [0.001/0.6]? Uncertainty in W2mag
(e_w2mpropm)
237- 243 E7.3 --- E(BP/RP)c [-0.9/41.7]? Corrected E(BP/RP)
(phot-bp-rp-excess-factor-c)
245- 250 F6.3 [-] logfpm0 [-4/99] Logarithm probability density of
zero proper motion (log-fpm0)
252- 256 F5.3 --- pGal [0/0.5] XGBoost probability of the object
being a galaxy (p-gal)
258- 262 F5.3 --- pQSO [0.3/1] XGBoost probability of the object
being a quasar (p-qso)
264- 268 F5.3 --- pStar [0/0.5] XGBoost probability of the object
being a star (p-star)
270- 277 F8.4 --- zGaia [-99.99/6.2]? Redshift estimate from Gaia
DR3 QSO candidate table (z-gaia)
279- 285 E7.4 --- zphXGB [-0.12/5] Photometric redshift predicted
with XGBoost (z-ph-xgb)
287- 293 E7.4 --- zphTabN [-0.33/10] Photometric redshift predicted
with TabNet (zph-tab)
295- 300 F6.4 --- zphFTT [0/5.65] Photometric redshift predicted
with FT-Transformer (zph-ftt)
302- 307 F6.4 --- zph [0.02/5.1] Ensemble photometric redshift
(mean of zph-xgb, zph-tab, and zph-ftt)
(zph)
309- 314 E6.4 --- zxp-nn [0.0009/4.8]? Spectral redshift predicted
with RegNet using Gaia low-res
spectroscopy (z-xp-nn)
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 25-Feb-2026